Conventionally, as this kind of compressor impeller and an exhaust turbine supercharger, for example, there have been a compressor impeller and an exhaust turbine supercharger (hereinafter, referred to as a supercharger) described in Patent Document 1.
The compressor housing of the supercharger described in Patent Document 1 includes a housing body (9) that surrounds a compressor impeller (8). The housing body (9) has a facing surface (14) that is located radially outside of a blade (13A) of the compressor impeller (8) in the housing main body (9) and faces the blade (13A). A sealing member (15) having a substantially cylindrical shape and formed of a plastic material having a free-cutting property to the compressor impeller (8), which is also referred to as an abradable seal is provided on the facing surface (14).
A groove (15a) is formed over the entire circumference on the outer circumferential surface of the sealing member (15). Also, a recessed portion (14a) is formed over the entire circumference on the facing surface (14) facing the grooves (15a).
At the time of assembling the sealing member (15) to the housing main body (9), by inserting the sealing member (15) into the inner circumference of the facing surface (14) of the housing main body (9) in a state where a snap ring (22) is fitted to the groove (15a), the snap ring (22) is fitted to both the groove (15a) and the recessed portion (14a). In this way, the sealing member (15) is assembled to the facing surface (14) via the snap ring (22), so that the sealing member is less likely to escape the housing main body (9).
Furthermore, conventionally, there has been a technique of forming the sealing member on the facing surface of the housing main body by thermal spraying, and a technique of forming the sealing member by injection molding.